The invention relates to a valve operating system for a multi-cylinder internal combustion engine with at least one intake and exhaust valve per cylinder, with a camshaft, having cams and being supported in bearing brackets mounted on the cylinder head, for the actuation of the valves via a rocker lever arrangement.
U.S. Pat. No. 4,438,734, for example, discloses an internal combustion engine with an overhead camshaft which operates the cylinder valves via rocker arms all supported by bearing support structures which are interconnected by an integral connecting structure.
The related U.S. Pat. Nos. 4,887,563 and 4,907,550 show a valve actuating structure for an internal combustion engine with overhead valves operated by an overhead camshaft via a rocker arm arrangement which includes for one valve two parallel rocker arms, a main rocker arm and an auxiliary rocker arm which are actuated by different cams, a main cam actuating the valve and providing appropriate valve timing for relatively low engine speed and an auxiliary cam actuating the auxiliary rocker arm and providing appropriate valve timing for high engine speeds. By pressurized oil supplied through passages in the rocker arm support shaft the auxiliary rocker arms are coupled with the main rocker arms during high engine speeds so that the valve timing of the auxiliary rocker arms is superimposed on the main rocker arms. The auxiliary rocker arms are held in contact with the cams via a spring structure disposed below the auxiliary rocker arm, that is, between the auxiliary rocker arm and the engine cylinder head.
The Honda publication, CIVIC, Technology and Data, List 4, Page 8, as of August, 1991, "design of a valve operating system", describes a valve operating system with a spring support element disposed between the upper side of an auxiliary rocker arm and the cylinder head cover and presses the auxiliary rocker arm against an associated cam of the camshaft in order to keep the auxiliary rocker arm in contact with the associated cam when the auxiliary rocker arm is decoupled from the main rocker arm.
The object of the present invention is to provide a considerably more compact valve operating system which facilitates assembly of the valve operating mechanism.